Polyesters reacted with tolylene dhsocyanate



United States atent 2,760,953 POLYESTERS REACTED WITH TOLYLENE DIISOCYANATE Nelson V. Seeger, Silver Lake, Ohio, assignor, by mesne assignments, to The Goodyear Tire & Rubber Company, a corporation of Ohio No Drawing. Application September 4, 1952, Serial No. 307,900 Claims. (Cl. 260-75) This invention relates to synthetic polymeric materials and to methods of preparing the same. More particularly it relates to modified polyesters which possess elastomeric, rubber-like qualities and to improved methods for their preparation. Still more particularly it relates to polyesters which have been modified by reaction with an organic diisocyanate and an additional bifunctional reactant to form an interpolymer.

The polyesters are formed, for example, by the condensation of a dibasic carboxylic acid with a glycol. The condensation reaction proceeds with the elimination of water to yield a linear polyester which is usually of a viscous, syrupy or wax-like consistency at room temperature.

As is determined by the materials and amounts thereof used in its formation, the linear polyester may contain terminal carboxyl or hydroxyl groups depending upon whether an acid or a glycol was the last compound to react in the formation of the linear molecule. The linear polyester is then lengthened further by reaction between these hydrogen-bearing terminal groups and a bifunctional material reactive therewith, such as a diisocyanate, with the formation of what may be referred to as a chainextended polymer. The linkages formed by the reaction of the terminal groups of the polyester with a diisocyanate, for example, are a urethane linkage (f H (-0i3I I-) in the case of a terminal OH group, and principally an amide linkage in the case of. a terminal --COOH group. Since each of these linkages contains hydrogen available for reaction with an additional bifunctional material such as a diisocyanate, it is possible to cross-link the chain-extended polymer at various points along its chain.

Depending upon many variables in their preparation, the modified polymers will vary considerably in their physical characteristics to include soft wax-like materials, elastomeric rubber-like materials, hard fiber-forming materials, tough leather-like. materials, and hard, infusible resinous materials. The present invention pertains to an improved modified interpolymer which has elastomeric,

rubber-like properties.

The cross-linking or curing which occurs as the result of reaction between the NCO groups of the diisocyanate and the available reactive hydrogen in they chain.- extended polymer is accompanied by the generation of gas. This gas, which is believed to be CO2, remains trapped in the mass with resulting blisters or bubbles in the cured product. To eliminate the trapped gas, it has been necessary to precure the material, during which time most of the gas is generated, remove the. material. from the oven or press, remill the material to dissipate the trapped gas, and return the gas-free material to the press, or oven, for final cure. This procedure is both time-consuming and expensive because of the many handling operations required to produce a satisfactory cured product. reduce the time of cure required to produce a satisfactory product from modified polyester. It is a further object It is therefore an object of this invention. to

to eliminate the blisters or gas bubbles in the cured product without the necessity of precure and rehandling of the raw material. It is another object to reduce the number of handling operations in the fabrication of a satisfactory cured product. Still another object is to produce a new modified polyester which is fast curing at elevated temperatures but which does not harden or cure appreciably faster than the usual modified polyesters at normal room temperatures. An additional object is to produce modified polyesters which possess improved physical properties. Other objects will appear as the description proceeds.

The particular polyesters used in the practice of this invention are similar to those described in my co-pending application, Serial No. 170,056, now abandoned. As described therein, the unmodified polyester is prepared in its simplest form from two bifunctional ingredients, one being a dibasic carboxylic acid and the other being a glycol. In addition, a wide variety of complex polyesters may be formed by the reaction of a plurality of acids and glycols. In preparing the polyester it is possible to use ester mixtures such as a physical mixture of ethylene adipate and 1,2-propylene adipate as well as mixed esters such as that resulting from the reaction of a mixture of ethylene glycol and 1,2-propylene glycol with adipic acid. The reaction proceeds with the elimination of water to yield a long chain molecule containing a succession of ester groups and terminated by either hydroxyl or carboxyl radicals. The reaction may be represented by the followingequation:

wherein R and R denote divalent organic radicals such as hydrocarbon radicals, and n is a positive whole number denoting the degree of polymerization of the polyester formed.

In the preparation of the polyester, it is possible to obtain products of varying molecular weight, depending in part upon the molecular weight of the reactants and in part upon the degree of polymerization of the reactants or the number of ester units in the polyester chain. While the average molecular weight of the polyester will, of course, vary depending upon the particular acids and glycols used, the average number of these ester groups present in the polyester chain must be held within certain limits in order to permit subsequent modification to field a satisfactory rubber-like polymer. A convenient method of measuring the degree of polymerization of the polyester is to determine the average number of carboxyl and hydroxyl groups in a given amount of the linear extended polyester. The acid number (milligrams of KOH per gram of polyester using phenolphthalein as an indicator) is a measure of the number of terminal carboxylz groups" in the polyester. The hydroxyl number, which is a measure of the number of terminal hydroxyl groups present, is determined by adding pyridine and acetic anhyd'ride to the polyester and titrating the acetic acid formed with KOH as described in Ind. Eng. Chem. Anal. Ed. 16, 54l49 and in Ind. Eng. Chem. Anal. Ed. 17,. 394 (11945)). The hydroxyl number is: defined as milligrams of KOH per gram of polyester The sum of the acid number and the hydroxyl number, which will be referred to as the reactive number, is an indication of the average number of terminal groups present in the polyester product which in turn is an indication of the number'of molecules in the. mass and the degree of poly merization. A polyester containing long chain molecules will have a relatively low reactive number, while a polyester containing short chain molecules Will' possess a higher reactive number.

As described in my co-pending application Serial No. 170,056, a rubber-like polymer is produced from a polyester having a reactive number from 30 to 152. In preferred practice, a polyester having a reactive number from 50 to 65 is employed. In addition, the acid number going to make up the reactive number is held to a maximum of 12 and preferably 5 or less. The acid num her is conveniently controlled by providing an approximate 20 mol per cent excess of glycol in the preparation of the polyester.

In the chain extension of a polyester possessing an acid number and hydroxyl number within the critical range indicated, a controlled amount of a particular diisocyanate is added to the polyester accomplishing the formation of the processible, storable uncured polymer by the use of an increment of diisocyanate which permits the polyester to chain-extend without cross-linking, as described in my co-pending application, Serial No. 170,056. When this diisocyanate-modified chain-extended polyester is subsequently cross-linked and cured by reaction with a second increment of diisocyanate, the problem of gas formation or blisters arises. It has now been discovered that the addition of a small amount of another bifunctional additive, in addition to the diisocyanate added to chainextend the unmodified polyester, will produce an un cured chain-extended modified polyester which will cross-- link or cure, when reacted with additional diisocyanate, in a shorter time and with the elimination of blisters in the cured product and which will at the same time retain its processible, storable characteristics.

The bifunctional additives which have been found to produce this unexpected result may be represented by the general formula X-- "X in which R" represents a divalent organic radical such as an aliphatic, or aromatic divalent radical, X represents either a NHz or a COOH group and X is a functional group containing at least one active, available hydrogen such as a primary amino, secondary amino, carboxyl, or hydroxyl group. Compounds falling within this definition would include diamines, dibasic carboxylic acids, amino acids, hydroxy acids, amino alcohols, and the ureas, guanidines, and thioureas which contain NHz groups. According to the practice of this invention, the bifunctional additive described must be used in an amount such that the sum of NH2 equivalents and CCOH equivalents present in the bifunctional additive shall be from 0.06 to 0.24 equivalent per mol of polyester. Smaller amounts result in a finished product whose cure rate has not been increased and whose blister forming has not been materially reduced. Greater amounts produce an uncured modified product which does not possess the required binaging or processing properties as described in my copending application referred to above.

Using the polyester formed as represented by Equation 1 above, the reactions between the polyester, the diisocyanate and the bifunctional additive may be typically represented by the following equations:

in which R" and R represent divalent organic radicals such as aliphatic or aromatic radicals and m represents a positive whole number denoting the number of segments in the modified chain-extended interpolymer.

The underlined hydrogens represent those available for reaction with the --NCO groups in the polyisocyanates used to cross-link or cure the chain-extended polyester. The products resulting from the reactions represented by the above equations may be referred to as (2) polyesteramide-urea-urethanes, (3) polyester-amideurethane-urethanes, and (4) polyester-amide-amide-urethanes. Other configurations are also possible if dibasic carboxylic acids or hydroxy acids are used as the additional bifunctional reactant. In each case an interpolymer is formed possessing controlled amounts of urea, amide, or urethane linkages located at the end of and outside of the polyester segments in the chain-extended polyester. The arrangement of the amide, urea, and urethane linkages along the chain can be either random or ordered depending upon the manner in which the bifunctional additive is reacted with the polyester-diisocyanate mixture. If all of the additive and diisocyanate are added together to the polyester, a random interpolymer results. If the additive is reacted with the polyester-diisocyanate mixture in increments, or if the additive has been withheld from the reaction mixture until the polyester and diisocyanate have been partially reacted, an ordered interpolymer results. In either case a product is formed which will cure faster than the polyester modified by diisocyanate only and which will not require additional handling to remove trapped gas. It has also been observed that the ordered interpolymer possesses improved physical properties.

The particular diisocyanates with which this invention is concerned are the tolylene diisocyanates, such as 2,5- tolylene diisocyanate and particularly the meta tolylene diisocyanate, such as 2,6-tolylene diisocyanate; 3,5-tolylene diisocyanate and preferably 2,4-tolylene diisocyanate or mixtures thereof, such as mixtures of the 2,4- and 2,6-isomers. It has been pointed out in my co-pending application Serial Number 305,914 that the critical range of diisocyanate which must be used to modify the polyester in order to produce a satisfactory rubber-like polymer is from 0.85 to 1.10 mols per mol of polyester. A preferred range is from 0.90 to 1.00 mol of diisocyanate per mol of polyester while optimum results are obtained in a range from 0.94 to 1.00. An additional amount of diisocyanate is required here to satisfy the active hydrogens present in the bifunctional additive. Therefore, the total amount of diisocyanate required to chain-extend the polyester in order to produce a processible, storable, fast-curing interpolymer which does not produce blisters in the cured product will be equal to the sum of from 0.85 to 1.10 mols per mol of polyester and a molar amount equivalent to the mols of bifunctional additive used. It is possible to employ a mixture of tolylene diisocyanates in the preparation of the chain-extended polyl a a awed-sea ester so long as the total )amount of the :diisocya-nate used falls Within the range indicated. While certain other diisocyanates will not produo: the desired results if used in an amount covered by the critical range specified, it .is to be understood that the .tolylene diisocyanates are not necessarily the only diisocyanates which are operative for the purposes of this invention, but rather represent those which produce the desired results when employed in an amount falling within the critical range indicated.

After the interpolymer has been formed, it is prepared for curing by adding more diisocyanate or other conventional curing materials, such as alkyl ethers of hexamet'hylol melamineywith a 2,4-diha'lo :naphthol as accelerator. Polyisocyanates such as 4,4',4 -triisocyanto triphenyl methane, "1,3,5 -t-r'iisocyanto benzene, and 2,4,6- triisocyanto' toluene, may also be used to effect a cure. Any organic diisocyanate, p'olyisocyanate, ormixtures of diisocyanates, polyisocyanates, -'or both, may be added in this step. It may be the same or a difierent' diisocyanate than that used in the formation of "the chain-extended polyester, or it may be a diiso'cyanate other than those listed above. A convenient method of adding the tolylene diisocyanate to be used either =i-n the formation of the chain-extended polymer or as a curing agent 'for the interpolymer is in the form of one of its dimers such as the dimer of 2,4-toly'lene diisocyanate of the following formula: 1

The dimer is less toxic than the monomeric material. The amount, of polyisocyanate added-toeifect a cure must be controlled so as to provide a total number of -NCO equivalent-s present-in the cured material, including that added in the formation of the chain extended polyester, equal to the sum of from 2.80 to 3.20 equivalents of -NCO per mol of polyester and twice the molar amount of bifunctional additive used in the preparation of the interpolymer. Smaller amounts-of polyisocyanate added to cure the interpolym'er'will:result in an uncured product. The use of greater amounts is a waste of material with no improved properties in the" cured product, and in some cases produces a cured materialhaving properties more resinous than rubber-like. 1f a triisocyanate or tetraisocyanate is used to effect a cure, not as much material, on a mol-tibasis, need be used since the curing or cross-linking of the linear molecules depends upon the number of -NCO groups present in the cur ing agent. For example, if 0.40 mol of a 'diisocyanate .gives .a satisfactory cure 'of the interpolymer, the use .of approximately 0.20 mol of.,a tetra-isocyanate will .result in a similar state of cure.

The actual curing of thefinterpolymer is accomplished by methods known to those skilled in the art. The time and temperature required to eifect the'best cure for any particular material Will, of course, vary as in the case with the curing -of conventional natural rubber compounds. The cure for best results should be accomplished by the meet dry heat since exposure of the interpolymer to hot water or steam results "in a partial degradation of the cured material.

A variety of acids and g'lycols may be used in *the preparation of thepolyester. 'iA'ny dibasic-carboxy lic acid containing at least "carbon-atoms, and preferably those whose carboxyl groups areattached to'terminal carbons, may be used including succinic, glutaric, adipic, pimelic, 'suberic, azelaic, sebac'ic, malonic, brassylic, tartaric, 'maleic, ma'lic, furnaric, "d-ilinoleic,v thiobutyric, diphen'ic', isophthalic, terephthalic, hexahydroterephthalic, p-phenylene diacetic, dihydromuconic, and B-methyladipic acids. For best results the unsaturated acids should be .used .in mixture with era ssaturated acid in anzamount snot 6 to exceed 5 mol per cent of the mixture. The presence of a small amount of unsaturation :in the gpel-yester is often desirable if cheaper curing or cross-linking agents, suchas for example, sulfur, benzoyl peroxide or tertiary butyl hydroperoxide, are to be used. Higher degrees of unsaturation in the polyester result in cured products which do not have the outstanding physical properties possessed by the products produced from polyesters containing no unsaturation or a relatively small amount of unsaturation.

Any glycol may be used in the formation of the polyester including ethylene, propylene-1,2, propylene-1,3, diethylene, triethylene, butylene, pentamethylene, hexamethylene, decamethylene, dodecamethylene, and N,-N- diet-hanolaniline, glycerine mono ethers, and thiodiglycol.

Specific examples of thebifunctional additives which may be used in the practice of this invention are:

(1) The diamines which contain at least one primary amino group including as representative examples ethylene, propylene 1,2, tetramethylene 1,4, hexamethylene 1,6, decamethylene 1,10, .isopropyl amino propylamine, 3,3-diamino dipropyl ether, benzidine, diamino-diphenyl methane, p-phenylene, m-phenylene and the meta 'tolylene diamines.

(2) The primary amino alcohols including, as representative examples, .ethanolamine, 3 amino-propanol', 4 amino butanol, 6 amino hexanol, and 10 aminodecanol.

(3) The dibasic carboxylicacids including, as representative examples, those listed under the materials available for the preparation of the polyester.

(4) The ureas, guanidines, and thioureas containing an --NH2 group including, as representative examples, urea, thiourea, phenyl guanidi'ne, methyl urea, phenyl thiourea, phenyl urea, and-methyl .thiourea.

(5) The amino carboxylic acids including, as representative examples, glycine, amino propionic, aminoca- .proic, aminononanoic, and amino undecanoic acids.

(6) The hydroxy carboxylic acids including, as representative examples, ;gly.collic, hydroxycaproic, and hydroXydecanoic acids.

Any mixture of these -=bifunctional additives may be used so long as the total number of COOH and NH2 equivalents is held within thecritical range indicated.

Listed below are the reactants which are used to form particular polyesters which, ;,When modified by tolylene diisocyanate and one or more bifunctional additives and subsequently mixed with asuitable curing or cross-linking agent, will produce a material which is 'fast to cure at elevated temperatures, slow to cure .atroom temperature, and free of blisters and which possess improved physical properties. 4

1. Ethylene glycol plus adipic acid.

2. Propylene glycol-1,2 plus adipic acid.

3. Ethylene glycol 80.mol per-cent), propylene glycol 1,2 (20 mol per cent) plus adipic acid.

4.. Ethylene glycol mol per cent), propylene glycol 1,2 (20 molper cent) plus azelaic acid.

5. Ethylene glycol (80 'mol per cent), propylene glycol 1,2 (20 mol percent) plus sebacic aci'd.

6. Ethylene glycol ('80tmol per cent), propylene glycol 1,2 (20 mol percent) xplus dilinoleic acid (20 molper cent), adipic acid (80111101 ,per cent). I

7. Ethylene glycol (:80 mol per cent.) glycerine monoethyl ether .(20 mol per cent), plus adipic acid.

8. Ethylene glycol (80 mol per cent), butyleneaglycol- 1,4 (20 mol per cent), plus'adipicacid.

9. Ethylene glycol ('80 mol percent), propylene glycol- 1,3 (20molper'cents) plus adipicacid. I Y

10. Ethylene glycol (80 :mol per cent), :pentane diol 1,5 (20 mol per cent) plus'adipic acid.

l-l. Ethylene glyco1(80 mol-per cent)., gl-ycerine.mono- .isopropyl ether (20 molper cent.) rplusadipic acid.

:12. Ethylene glycol (80 mol per cent), {propylene glycol-1,2 (20 mol,peracenta) plus vmaleic acid (from 6 to 6 mol per cent), adipic acid (from 97 to 94 mol per cent). 13. Ethyleneglycol (80 mol per cent), propylene glycol-1,2 (from 18 to mol per cent), dihydroxyethyl aniline (from 2 to mol per cent) plus adipic acid.

14. Ethylene glycol (80 mol per cent), diethylene glycol mol per cent) plus adipic acid.

15. Ethylene glycol (from 90 to 10 mol per cent), propylene glycol-1,2 (from 10 to 90 mol per cent) plus adipic acid.

16. Ethylene glycol (from 90 to 10 mol per cent), propylene glycol-1,2 (from 10 to 90 mol per cent) plus azelaic acid.

Of particular interest are the interpolymers resulting from (1) Polyethylene adipate modified by tolylene dissocyanate, andby benzidine, 4,4'-diamino diphenyl methane, meta tolylene diamine, adipic acid, dilinoleic acid or mixtures thereof.

(2) Polypropylene 1,2-adipate modified by tolylene diisocyanate and by benzidine, 4,4-diamino diphenyl methane, meta tolylene diamine, adipic acid, dilinoleic acid or mixtures thereof.

(3) Polyethylene (80 mol per cent), propylene 1,2 (20 mol per cent) adipate modified by tolylene diisocyanate and by benzidine, meta tolylene diamine, adipic acid, dilinoleic acid, 4,4'-diamino diphenyl methane or mixtures thereof.

(4) Polyethylene (80 mol per cent), propylene 1,2 (20 mol per cent) azelate modified by tolylene diisocyanate and by benzidine, 4,4'-diamino diphenyl methane, meta tolylene diamine, adipic acid, dilinoleic acid or mixtures thereof.

(5) Polyethylene (80 mol per cent), propylene 1,2 (20 mol per cent) sebacate modified by tolylene diisocyanate and by benzidine, 4,4-diamino diphenyl methane, meta tolylene diamine, adipic acid, dilinoleic acid or mixtures thereof.

These interpolymers, when cured, have been found to possess outstanding physical properties.

The elastomeric reaction products prepared according to the practices of this invention are, in general, useful in those applications where natural rubber or rubber-like materials are used. In particular they may be used in tires, belts, hose, sheet packing, gaskets, molded goods,

floor mats, dipped goods, sheeting, tank lining, soles,

heels, covered rolls, and other mechanical and industrial goods.

The following examples in which parts are by weight are illustrative of the preparation of the modified polyesters prepared according to the teachings of this invention.

EXAMPLE 1 Adipic acid (3515 parts) was placed in a 5 liter, 3-necked flask fitted with a stirrer, thermo-couple well, gas inlet tube, distilling head, and condenser. To the acid were added 1064 parts of ethylene glycol and 869 parts of propylene 1,2 glycol. The molar ratio of dibasic acid to glycol is 1:1.19. The mixture was heated to 130160 C. until most of the water had distilled off The temperature was then gradually raised to 200 C., the pressure being gradually reduced to 20 mm. and nitrogen being bubbled through the melt. After 23% hours a soft white waxy solid was obtained. Determinations showed the acid number to be 3.5 and the hydroxyl number to be 58.6.

EXAMPLE 2 The polyester (200 parts) prepared according to Example 1 was heated in an open iron kettle to 120 C. To this were added 1.11 mols of 2,4 tolylene diisocyanate per mol of polyester and 0.06 mol of hexamethylene diamine per mol of polyester. After 15 minutes of mixing the material was poured into a waxed aluminum tray and baked for 8 hours at 120 C. The resulting in- 8 terpolymer had excellent processing characteristics on a rubber mill.

EXAMPLE 3 This interpolymer was prepared in the same manner as Example 2 except adipic acid was used as a molar replacement for the hexamethylene diamine. This product too had good processing characteristics on a rubber mill.

EXAMPLE 4 This interpolymer was prepared in the same manner as Example 2 except ethanolamine was used as a molar replacement for the hexamethylene diamine. The processing characteristics of the material were good.

The uncured interpolymers prepared according to Examples 2, 3 and 4 were mixed with 0.45 mol of additional 2,4-tolylene diisocyanate per mol of polyester and cured for 30 minutes at 300 F. with no precure. The cured material contained no blisters. The results obtained from physical tests showed the cured material to have excellent physical properties. Similar polymers prepared without the bifunctional additives resulted in cured material which was blistered unless the polymer was precured, removed from the press, remilled to remove the blisters formed and returned to the press for final cure.

EXAMPLE 5 A polyester was prepared from adipic acid, ethylene glycol and propylene glycol in the proportions and according to the procedure shown in Example 1. Analysis showed this polyester to have a hydroxyl number of 61.1 and an acid number of 1.9. To 2300 grams (1.29 mols) of this polyester were added 222 grams (1.266 mols) of a mixture of 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate having a purity of 99.3%. The mixture was reacted for 10 minutes at C. under constant agitation after which time 6.2 grams .0508 mol) of 2,4- tolylene diamine were added. After an additional 10 minutes of mixing, 8.9 grams (.0508 mol) of the mixture of 2,4- and 2,6-tolylene diisocyanates were added. The reaction mixture was stirred for an additional 10 minutes after which it was poured into a waxed aluminum tray and baked for 16 hours at 129 C. The modified but uncured interpolymer showed the following results when aged at room temperature for the times indicated:

Table Age of sample Percent Intrinsic Mooney Plastic Gel Viscosity Plasticity Flow None 1. 19 28 31 None 1. 45 37 73 None 1.37 40 73 None 1. 47 35 79 56 days None 1. 38 39 89 The percent gel and intrinsic viscosity were determined by methods well known in the art. The Mooney plasticities were run at 212 F. using a large rotor. The plastic flow test was run by extruding the material through an orifice under a constant pressure (500 pounds per square inch) and at a constant temperature (212 F.) and recording the time (in seconds) required to extrude a given length (1 inch) through the orifice.

The test data shown in the table indicates that there is no significant change in the physical properties of the uncured modified interpolymer even after aging for 8 weeks at room temperature, showing that the product is stable and storable.

EXAMPLE 6 The uncured modified interpolymer prepared according to Example was then mixed on a mill with the following ingredients. Parts are shown by weight Modified interpolymer 100.00

The polyisocyanate mixture used was prepared by the phosgenation of a mixture of primary polyamines formed from aniline and formaldehyde. The specific polyisocyanate mixture used had an amine equivalent of approximately 135. The preparation of these polyisocyanate mixtures is described in co-pending application Serial Number 206,506 filed January 17, 1951.

Test sheets from the compound interpolymer cured for minutes at 280 F. showed a tensile strength of 4100 pounds per square inch, an elongation at break of 630% and a hardness of 58 (Shore Durometer-Type A). Tests run according to the Bureau of Standards Abrasion determination on a sample cured for twenty minutes at 260 F. showed an abrasion value of 348.

This application is a continuation-in-part of my copending application Serial Number 187,695 filed September 29, 1950, now U. S. Patent 2,625,531.

While certain representative embodiments and details have been shown for the purpose of illustrating the invention, it will be apparent to those skilled in this art that various changes and modifications may be made therein without departing from the spirit or scope of the invention. I

I claim:

1. The processible, storable elastomeric reaction product resulting from the reaction of a mixture comprising (A) a polyester prepared from bifunctional ingredients including at least one dibasic carboxylic acid containing at least 3 carbons and at least one glycol, said polyester having a hydroxyl number from to 140 and an acid number from O to 12, and (B) at least one bifunctional additive selected from the group consisting of diamines, amino alcohols, dibasic carboxylic acids, amino carboxylic acids, hydroxy carboxylic acids, and the ureas, guanidines and thioureas containing a primary amino group, said bifunctional additive containing at least one reactive group selected from the group consisting of primary amino and carboxyl and being used in an amount such that the total number of NH2 and COOH equivalents present in said bifunctional reactant shall be from 0.06 to 0.24 equivalent per mol of polyester, and (C) at least one tolylene diisocyanate, the diisocyanate being used in an amount equal to the sum of from 0.85 mol to 1.10 mols of diisocyanate per mol of polyester and the molar amount of diisocyanate equivalent to the mols of said bifunctional additive used.

2. The processible, storable elastomeric reaction product defined by claim 1 in which the diisocyanate is used in an amount equal to the sum of from 0.90 to 1.00 mol per mol of polyester and a molar amount equivalent to the mols of bifunctional additive used.

3. The processible, storable elastomeric reaction product defined by claim 1 in which the bifunctional additive contains at least one primary amino group.

4. The processible, storable elastomeric reaction product defined by claim 1 in which the bifunctional additive is at least one dibasic carboxylic acid.

5. The processible, storable elastomeric reaction product defined by claim 1 in which the polyester is prepared from adipic acid, ethylene glycol, and propylene glycol.

6. The processible, storable elastomeric reaction product defined by claim 2 in which at least one meta tolylene diisocyanate is used in' an amount equal to the sum of from 0.94 to 1.00 mol per mol of polyester and a molar amount equivalent to the mols of bifunctional additive used.

' 7. The processible, storable elastomeric reaction prod- 10 uct defined by claim 6 in which the polyester is prepared from adipic acid, ethylene glycol and propylene glycol.

8. The processible, storable elastomeric reaction product defined by claim 7 in which the bifunctional additive contains at least one primary amino group.

9. The processible, storable elastomeric reaction product defined by claim 8 in which the bifunctional additive is tolylene diamine.

10. The processible, storable elastomeric reaction product defined by claim 3 in which the bifunctional additive is tolylene diamine.

11. The processible, storable elastomeric reaction product defined by claim 4 in which the bifunctional additive is adipic acid.

12. The processible, storable elastomeric reaction product defined by claim 4 in which the bifunctional additive is dilinoleic acid.

13. The processible, storable elastomeric reaction product defined my claim 5 in which the polyester has a reactive number from 50 to 65 and an acid number from O to 12. a

14. The process for making a'processible, storable elastomeric reaction product which comprises reacting together a mixture of (A) a polyester prepared from bifunctional ingredients including at least one dibasic carboxylic acid containing at least 3 carbons and at least one glycol, said polyester having a hydroxyl number from 30 to and an acid number from 0 to 12, and (B) at least one bifunctional additive selected from the group consisting of diamines, amino alcohols, dibasic carboxylic acids, amino carboxylic acids, hydroxy carboxylic acids, and the ureas, guanidines and thioureas containing a primary amino group, said bifunctional additive containing at least one reactive group selected from the group consisting of primary amino and carboxyl and being used in an amount such that the total number of --NH2 and COOH equivalents present in said bifunctional reactant shall be from 0.06 to 0.24 equivalent per mol of polyester, and (C) at least one tolylene diisocyanate, the diisocyanate being used in an amount equal to the sum of from 0.85 mol to 1.10 mols of diisocyanate per mol of polyester and the molar amount of diisocyanate equivalent to the mols of said bifunctional' additive used.

15. The process defined by claim 14 in which the tolylene diisocyanate is used in an amount equal to the sum of from 0.90 to 1.00 mol per mol of polyester and a molar amount equivalent to the mols of bifunctional additive used.

16. The process defined by claim 14 in which the bifunctional additive contains at least one primary amino group. 1 i

17. The process defined by claim 15 in which at least one meta tolylene diisocyanate is used in an amount equal to the sum of from 0.94 to 1.00 mol per mol of polyester and a molar amount equivalent to the mols of bifunctional additive used.

18. The process for making a cured elastomeric composition which comprises reacting the product prepared according to claim 14 with a sufiicient amount of at least one polyisocyanateto bring the total number of NCO equivalents present in said cured mixture to the sum of from 2.80 to 3.20 equivalents of NCO per mol of said polyester and twice the molar amount of bifunctional additive used in the preparation of said elastomeric reaction product.

19. The cured elastomeric composition prepared according to the process defined by claim 18.

20. An article comprising the cured elastomeric composition defined by claim 19.

Schmidt et a1. Dec. 9, 1952 Seeger Jan. 13, 1953 

1. THE PROCESSIBLE, STORABLE ELASTOMERIC REACTION PRODUCT RESULTING FROM THE REACTION OF A MIXTURE COMPRISING (A) A POLYESTER PREPARED FROM BIFUNCTIONAL INGREDIENTS INCLUDING AT LEAST ONE DIBASIC CARBOXYLIC ACID CONTAINING AT LEAST 3 CARBONS AND AT LEAST ONE GLYCOL, SAID POLYESTER HAVING A HYDROXYL NUMBER FROM 30 TO 140 AND AN ACID NUMBER FROM 0 TO 12 AND (B) AT LEAST ONE BIFUNCTIONAL ADDITIVE SELECTED FROM THE GROUP CONSISTING OF DIAMINES, AMINO ALCOHOLS, DIBASIC CARBOXYLIC ACIDS, AMINO CARBOXYLIC ACIDS, HYDROXY CARBOXYLIC ACIDS AND THE UREAS, GUANIDINES AND THIOUREAS CONTAINNG A PRIMARY AMINO GROUP, SAID BIFUNCTIONAL ADDITIVE CONTAINING AT LEAST ONE REACTIVE GROUP SELECTED FROM THE GROUP CONSISTING OF PRIMARY AMINO AND CARBOXYL AND BEING USED IN AN AMOUNT SUCH THAT THE TOTAL NUMBER OF -NH2 AND -COOH EQUIVALENTS PRESENT IN SAID BIFUNCTIONAL REACTANT SHALL BE FROM 0.06 TO 0.24 EQUIVALENT PER MOL OF POLYESTER, AND (C) AT LEAST ONE TOLYLENE DIISOCYANATE,THE DIISOCYANATE BEING USED IN AN AMOUNT EQUAL TO THE SUM OF FROM 0.85 MOL TO 1.10 MOLS OF DIISOCYANATE PER MOL OF POLYESTER AND THE MOLAR AMOUNT OF DIISOCYANATE EQUIVALENT TO THE MOLS OF SAID BIFUNSTIONAL ADDITIVE USED. 